1. Field of the Invention
The present invention relates to an optical device having a dust removal capability and an optical apparatus using the optical device.
2. Description of the Related Art
Many single lens reflex digital cameras are configured to use interchangeable lenses and hence a half-silvered mirror and other optical devices incorporated in a digital camera are exposed to the atmosphere when the currently attached lens is interchanged with another one. Dust and other dirt in the atmosphere therefore adhere to the surface of the half-silvered mirror. The dust and other dirt having adhered to the half-silvered mirror form shadows in an image and hence disadvantageously cause decrease in image quality.
To address the problem, the following technique has been proposed: A piezoelectric device is disposed along the periphery of an optical device, and an AC voltage is applied to the piezoelectric device so that it vibrates. The optical device thus vibrates and removes dust and other dirt thereon (see JP-A-2003-319222, FIG. 5 and other figures, for example).